Surface acoustic wave-matched filter and differential detector for demodulating spread spectrum signals

摘要

A surface acoustic wave-matched filter is disclosed which comprises: an input transducer provided on a piezoelectric substrate surface; a first output transducer, that is, a forward output transducer encoded in correspondence to a pseudo-noise code sequence for spectrum spreading and provided on the substrate surface; and a second output transducer, that is, a backward output transducer encoded in correspondence to the pseudo-noise sequence code and provided on the substrate surface at the succeeding to the forward output transducer by the length of the pseudo-noise code sequence as viewed from the input transducer. With the use of the surface acoustic wave-matched filter, it is possible to realize a differential detector for demodulating spread spectrum signals.